Quaternary taurine type compounds as surface-active agents



United States Patent ()iiice 2,697,l l6 Patented Dec. 14, 1 954 QUATERNARY TAURINE- TYPE-COMPOUNDS} AS SURFACE-ACTIVE AGENTS No Drawing. Applicationseptember 25, 1951, Serial No. 248,279

The, present invention relates to new and useful surface active agents. More particularly, the invention relates to surface-active agents of an ionic nature which contains both, an anionic group and, a. cationic group within the same molecule and to. a method for preparing these agents.

Pursuant. to the invention it has been. discovered that new and useful ampholytic surface-active agents having both cationic and anionic characteristics may be pre pared, by reacting a molar excess of an alkyl aryl methylene halide or an aryl methylene-halide with an -N-alkyl amino alkane' sulfonate in the presence of a neutralizing agent. The novel products may be illustrated by the following structural formula:

R AlcHfl.

I IR4SO;

wherein R1 and R2 are hydrogen or alkyl groups of from 1 to 24* carbon atoms, Ar is an: aryl hydrocarbon group, R3; is an alkyl group offrorn: 1 to 7 carbon atoms, and R4 is an alkylenegroup ofi'fromwl to 7' carbon atoms.

The. above compoundsare generally useful as surfaceactive agents. They are amphoteric in nature and their molecule as a whole forms a Zlwitter ion between the quaternary nitrogen group andthe sulfonicgroup. Thus, within a single compound, some of the beneficial aspects of both cationic and anionic surface-active agents are combined to give a product possessing distinct and unusual surface-active properties not exhibited by either cationic or anionic agents.

A further distinctive and desirable feature of the present compounds is that the quaternary nitrogen group is more strongly ionizable under certain conditions than an ordinary amino group would be in the same circumstances. For example, under alkaline conditions which are often encountered in applications of surface-active agents the present compounds exhibit the characteristics of free Zwitter ions and may be isolated as such, whereas amino sulfonates would not possess Zwitter ion characteristics under similar conditions.

The new compounds may be preferentially water-soluble or preferentially oil-soluble depending on the substituents on the aryl nucleus. The preferred group of compounds according to the invention is that containing a nuclear alkyl group of from 9 to 18 carbon atoms on each of the aryl groups. Such compounds are preferentially oil-soluble and are useful in lubricating and fuel oil compositions.

The preferentially oil-soluble compounds which are a particularly desirable species of this invention possess excellent dispersing properties in lubricating and fuel oil compositions. Sludge-forming materials normally present in fuel oils may be maintained in suspension for an indefinite period by these agents, thus avoiding undesirable sludge deposition and clogging of filters. The compounds are also very effective as anti-rust additives for fuel and lubricating oils.

The compounds according to the invention as illus trated in the above structural formula contain two aryl or alkaryl groups, each of which is connected by a methylene linkage to the nitrogen. Examples of suitable aryl groups are benzene, naphthalene, anthracene, toluene, xylene, mesitylene, etc., with benzene and toluene being preferred for their availability and the high degree of effectiveness characteristic of the compounds containing them. The nuclear alkyl substituents may be straightchain. or branched-chain in nature and. may vary. from 1 to 24' carbon atoms inlength. The alkyl groups may be derived from halogenated hydrocarbons, aliphatic alcohols and olefins including cracked petroleum fractions and: polymers of ethylene, propylene and butylene. For present purposes propylene polymers containing from 9 to 18 and, more specifically, from 12 to- 1-5- carbon atoms per molecule are preferred: because of their chemical stability derived from the characteristically moderate chain-branching of propylene polymers in-genera'l.

In the above structural formula illustrating the'invention, that portion: derived from the N'-alkyl amino-alka-ne sulfonate reactant is represented by the group:

N-CHr-CHzSOs- CH2 H3 R wherein R1 and R2 are hydrogen or alkyl groups of from 1 to 24 carbon atoms, R is a hydrogen or methyl group, and x is an integer of from 1 to 3.

This preferred group of compounds, according to the invention, may be prepared by chloromethylating benzene, toluene or xylene, or nuclear alkyl derivatives thereof, for example. A molar excess of the chloromethyl derivative, and preferably at least 2 molar proportions thereof, may then be reacted with sodium N-methyl taurate at a temperature of from about 50 to 100 C. in the presence of a neutralizing agent such as sodium hydroxide, sodium bicarbonate, sodium carbonate, lime, etc.

As a further illustration of the invention, the following specific examples are offered.

Example 1.Preparati0n of N,N-dibenzyl-N-methyltaurine A mixture of 40 parts of sodium N-methyltaurate, 70 parts of benzylchloride, 25 parts of sodium bicarbonate, 100 parts of ethanol and 175 parts of water was warmed with stirring to reflux temperature. After refluxing for 2 hours, the mixture was cooled, extracted with two 100- part portions of petroleum ether and the crude product was isolated by evaporation of solvents. The material was purified by recrystallization from ethyl alcohol to give a colorless, crystalline solid. Upon analysis, the solid was found to have a melting point of 236-237 C.

Example 2.-Preparation of N,N-di-(n0nylbenzyl)-N- methyltaurine A mixture of 40 parts of sodium N-methyltaurate, 168 parts of nonylbenzyl chloride, the nonyl group of which was derived from propylene trimer, 100 parts of ethyl alcohol and 75 parts of water was refluxed with stirring for 3 hours at C. The mixture was diluted with 50 parts of methanol and extracted with parts of petroleum ether. The water layer was removed and 3 the alcoholic solution washed with 100 parts of water followed by evaporation at 70 C. under reduced pressure to give 167 parts of a colorless solid.

Analyses. Calculated for Cad-157N038: percent N=2.45. Found: percent N=2.l4.

Example 3.--Preparatin of N,N-di-(dodecylbenzyZ)-N- methyltaurine A mixture of 53 parts of sodium N-methyltaurate, 28 parts of sodium bicarbonate, 210 parts of dodecylbenzyl chloride, the dodecyl group of which was derived from propylene tetramer, and 300 parts of ethyl alcohol was refluxed at 80 C. for 8 hours. The mixture was cooled, diluted with 100 parts of water and 20 parts of methanol and the water layer was removed. The alcoholic solution was diluted with 200 parts of petroleum ether and 150 parts of methanol and shaken. The oil layer was removed and the alcoholic solution evaporated to give 161 parts of a light-yellow, viscous liquid.

Analyses. Calculated for C41Hs9NO3S: percent N=2.l3. Found: percent N=1.94

Example 4.--Preparati0n of N,N-di-(kerylbenzyl)-N- methyltaurine A mixture of 32 parts of sodium N-methyltaurate, 17 parts of sodium bicarbonate, 85 parts of water, 300 parts of ethyl alcohol and 152 parts of dodecylbenzyl chloride, the dodecyl group of which was derived from a kerosene distillate containing approvimately 12 carbon atoms per molecule, was refluxed for 6 hours. The water layer was removed and the product was diluted with 100 parts of water and 100 parts of petroleum ether. The petroleum ether and water layers were removed and the alcohol layer containing the product was evaporated to give a viscous, yellow grease.

Example .Preparation of 2- [N ,N -di-( dodecyl-methylbenzyl) -N-ethylammonium-propane-1 -sulfonate A mixture of 189 parts of sodium 2-(N-ethylamino)- propane-l-sulfonate, 800 parts of dodecylmethylbenzyl 4 chloride, 84 parts of sodium bicarbonate, 378 parts of water and 500 parts of isopropanol was refluxed with stirring for eight hours. The water layer was removed and the product washed with water. The dried product was a pale-yellow, viscous liquid which weighed 870 parts.

In the above examples the parts given are on a weight basis unless otherwise specified.

I claim:

1. Compounds having the formula:

R AICH:

+ N-Rr-S O:

RgArCH: R:

wherein R1 and R2 are members of the group consisting of hydrogen and alkyl groups of from 1 to 24 carbon atoms, Ar is a mononuclear aryl hydrocarbon group, R3 is a member of the group consisting of methyl and ethyl, and R4 is a member of the group consisting of ethylene and propylene.

2. N,N-di-(alkyl aryl methylene)-N-methyl taurine in which the alkyl group contains from 1 to 24 carbon atoms and the aryl group is a mononuclear aryl hydrocarbon.

3. N,N-di-(alkylbenzyl)-N-methyl taurine in which the alkyl group contains from 9 to 18 carbon atoms.

4. N,N-dibenzyl-N-methyl taurine.

5. N,N-di-(alkylbenzyl)-N-methyl taurine in which the alkyl group is a propylene polymer containing from 12 to 15 carbon atoms.

6. N,N-di-(dodecylbenzyl)-N-methyl taurine.

7. 2-[N,N-di-(dodecyl-methylbenzyl) N ethyl ammonium]-propane-1-sulfonate.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,999,432 Ulrich et al. Apr. 30, 1935 2,376,911 Granacher et al. May 29, 1945 2,433,997 Linch Dec. 6, 1948 OTHER REFERENCES Chem. Abst. vol. 31, pp. 6198 and 6199 (1937). 

1. COMPOUNDS HAVING THE FORMULA: 